Nowadays, there is widespread agreement that the possibility of detecting and counting the CTCs can lead to important information in medical field.
In particular, this information can be used for defining a diagnosis, a treatment and a monitoring system of many forms of cancer.
Some known procedures for isolating and detecting the CTCs from blood include, for example, the use of magnetic beads coated with specific antibodies capable of recognizing specific cell-surface markers. Examples of commercial technologies based on an antibodies/surface markers interaction include the CellSearch System™ manufactured by Veridex.
However, the use of surface proteins as targets for isolating and detecting CTCs suffers from different problems which are, for example, a lack of unique biomarkers on CTCs, the exclusively isolation/detection of EpCAM+ epithelial cells and the impossibility to use the isolated cells for further analysis. Further problems linked to this approach are the slow speed (with CellSearch System™ only 8 analyses per day can be carried out) and high cost (about 350$ per analysis of materials only, 650$ including technical assistance in performing the analysis [Data by Istituto Oncologico Veneto, Padova]) due to the fact that purified antibodies are required for the isolation/detection.
Other known methods for detecting CTCs use physical properties (such as size or hardness) to discriminate tumour cells from non-tumour cells. These methods, however, has not been clinically validated.
Reviews of the current technology for detecting CTCs can be found in: “Circulating Tumour Cells: Liquid Biopsy of Cancer, C. Alix-Panabieres and K. Pantel, Clinical Chemistry 59: 1,110-118 (2013); and “Techniques for Label-Free Separation of Circulating Tumour Cells: from Historical Foundations to Recent Developments”, C. Jin et al, Lab Chip, 2013, DOI:10.1039/C3LC50625H.
Therefore, there is a huge need of developing alternative approaches capable of improving the detection of Circulating Tumour Cells that allow to overcome the drawbacks of the methods described in the state of the art.